Valve-tappet construction



Sept. 24, 1929. O ABBOTT, JR 1,729,468

VALVE TAPPET CONSTRUCTION Filed June 21, 1928 INVENTOR.

x7ar/an O. fibbott c/I."

A TTORNE Y.

Patentedj sept. 24, l929 I v v UNITED .STATES PATENT OFFICE- 0. when,511., or onossn rom'rn rank, mrcnrean VALVE-mart ni. cons'rnnc'rronApplication filed June 21,1923. Serial No. 287,134.

This invention relates to valve operating holding the valve on i'tsseat'. The spring may mechanism, and it has to do especially with an beassociated with the valve stem by means of improvement in a valve tappetconstruc i a washer like member 3 retained on the valve which is'primarily useful in conjunction with t m b a ll 4,

5 poppet valves. used largely 1 internal com- A push rod for the valveis shown at 5, the 55 bustion engines. lower end of which may be inassociation inYention Q l P PP withan open cam, and this tappet isslidably. 'stru ti iq W111 fiF P d m held by a suitable part of theengine construcner f. 0p1 andjll 1 g f 9 tion, as shown at 6.Atappet-adjusting screw the P y features 18 that'of qtlletness m isreferenced 7 which may beheld in adjusted operation. There are, however,other. feai i b 1 k t I tules of,the mventlon, amon whlch a be As bestshown in Fig. 2, the stem 1 doesnot mentloned the fact that the c eal QJ make direct contact with the tappet adjustment a be readfiy ze l-t tOnce ing screw as there is interposed between themadesucilianadl}1stment1sma mmmedover stem and the screw a member 10'which will 65 10.1155 Perlod if t 'Mot'eoverv the h hereafter be termed,for, convenience, a ball msm lsfifiectlve Over Wlde Ogden member. Asuitable socket construction is ance admstments, and the construction 15such provided for this ban, and for this Purpose as to compensate fortheexpansion of parts pt 20 upon becoming heated. Other features of the Iggg zz i f r rgffs so i gz; g g gz gizi g fi invention will appeardescnptlon rectly in the upper end of the tappet screw" gresses'whichmaybe of sufiicient size for the purpose Accordlng to the inventiona ball and socket or if -it is foundv to beiconvenient, a p

t e of ta et construction is provided in l i213 cb junctior i with. afluid for cushioning the i g fi gh be employed zfi 15 blow between theseparated parts when the g me e m some manner PPvalvemechanismopeigatestcactulatehthe valve; This Socket The mechanismcan e use wit t e conventime for wage tii iittf. .fii sviaraarssgsasfi1;; Valve and m lbs oPq-atmn the clearance 18 efthe construction whichmovement is effected 5 {acted y the ban msmg out of the Socket andbyreason of themecessary clearance between the fluid acts as a cushionbetween the socket I i and ball when the cam actuates the valve the Prod and the Valve stem- The Valve l In the accom an in drawings. stem isnot connected to the ball member but Fi 1 is a sec tiorizil iewtakenthrough the merely contacts with the upper fiat surface 85conshction showin the eneral arrange of the ball. Thus, in order toinsure that rela- .ment of the parts i g I tive movement takes placebetween the ball Fig. 2 is an enlarged section illustrating e k t h q a23$: li ig l z Wlth a g how the ban and i l mefiber functlon In tilribi' riial op r ltion 5f suih a taPP t 9o 40 figiii: s i dd dl ev t ohi llil t rating, in an ll the W h 1 1 exaggerated the re25:25:32?isfiseis iaiiz.5 a zzsea. gutomatlcany takes care of1the Ina-ccv alve stem contacts with the va lse stem and ig gg wlth the Va l s'teman e raises the valve against the action of the ,95

Fig. is a view illustrating the -modified spring 2.' When the campermits the tappet form; I to lower, the valve closes under the actionof In the accompanyin drawings the stem of the spring. Ordinarily thereis about .007 a poppet type valve is shown at 1, the same of an inchclearance between the valve tappet 5 being provided with suitable spring2 for and the valve stem, and the conventional tape and ball of theconstruction pet noiseis caused by the valve tappet rising up andstriking the valve stem.

1 In the present construction the usual clearance between the tappet andstem takes place between the ball and socket, as; above de- :scribed.This is efiected by r'eason of the spring 14 holding the ball member upagainst the valve stem and in .contact therewith. Accordingly, whenthepush "rod israised-by the cam, thetappet risesand the spring 114 is"compressed until the ball seats in the socket whereupon the valve stemis raised. All'internal combustion engines used in automotivevehicles,with which applicant is familiar, lubricate in one way oranother this valve -mechanis'm; some lubricate merely by 011 vapors,others by gravity flow of-oil,.,and

others by positive pumpsystem. Thep'resent invention is designed to takeadvantage of .this lubricating oil and use the same as a cushioningfluid.

It has been found in actual practice that the oil, accumulates muchafter the manner ef' the cam. At this time the oil which has ac:-

cumnlated, as shown, fills the clearance space between the ball and thesocket. It is thought that the oil 'flows. in between the ball andsocket not alone by gravity but that the flow is aided by the'partialvacuum produced when the ballrises up from the socket under the actionof spring 14. When the tappet again raises the valve, the oil forms acushion between the ball and socket thus eliminating the metallict'appet noise,

It will here be noted that at the point referenced 17 the space-betweenthe :ball and the'walls of the socket is relatively narrow thusproviding a restriction to the flow of the oil out from between the balland socket when the two members are brou ht together. This aids ininsuring an 'oil 1m of substantial thickness at the time the ball andsocket are brought together wherein the escape of-the oil is more orless retarded. This restriction .is efiected by reason of the ball andsocket being substantially hemispherical, and the oove 16 is providedprimarily-for regulat mg this restriction, as it will be appreciatedthat the deeper the groove the less the restriction. This groove alsoaids in. retaining the accumulation of oil.

The proposition of the restriction at 17 preventing the flow of oil backin between the ball'jand socket when'they are separated, more or lessnaturally presents itself. However,

the dwell period ofthe cam,-that'is, thep'eriod oil may be used fromtime to time,

'1', 7a9,4e i3 when the parts are. in the position shown in" I Fig. 2,is relatively long while the period .when' the valve is lifted and theparts are brou ht togetherfi's relatively short. Thus,

this ong period. is ample; to let the oil flow through the restrictionin between the ball andsocket. i

In operation, the flat side of the ball is at all times 1n contactwiththe end of the valve stem; The accumulation of oil in and around thecontacting surfaces ofthe ball and valve stem is in many instancessufiicient to hold the ballag ainst the valvestem by reason of thecapillary attraction, but it is preferred to also utilize the smallspring for this purpose to positively insure this'action. It will benoted that thesocket is closed so that the oil does .not flow throughthe-socket but is. trapped therein. a

.This construction has been found to be very advantageous in actualuse,'and a number of important features have been noted, Forexample,-the usual tappet clearance is in the neighborhood of .007 of aninch, but with this construction there 'is no noise in thetappetoperation where a clearance much greater than .007 occurs. Forexample, a test has shown that there is no tappet noise where theclearance is as great as .020. Moreover, the operation of the. valveconstruction in]- proves with" use. Thisoccurs by reason of the factthat in machining the ball and socket, certain irregularities are almostsure to occur so that certain highspots are present either in-the ball,in the socket, or both. 'When'first put into use, these high spots moreor less reak through the film of oil, and approximate a point to pointcontact, but. after use the two parts are-worn in so thatthe ball fitsperfectly in-the socket. There is no point to pointcontact but a surfaceto surface contact which does not break through the film of oil.

Moreover, the construction accommodates for inaccuracies in contactbetween the valve stem and push rod, as is shown in an exaggerjatedmanner in Fig.- 3. As shown in this figurethe valve stem is imperfect,having a projecting part 20. Thisis compensated for y. reason" of thefact thatthe ball is cocked a little but-still maintains the surface tosurface'contact and a quiet operation results.

There. are quite a number of causes for an imperfect contact of thisnature, but they need not gone into as one example will sufiice to showthe operation. 7

It is appreciatedthat different grades of ut it has beenfound thattheconstruction will work satisfactorily with all grades of oil whetherlight or heavy, as are commonly used in in- .ternalcombustion engines,In this regardit maybe pointed out that the construction isself-compensating for the expanding parts whenthey become heated. Whenthe parts become hot and expanded the ball and socket fit a littlecloser together, but at the same time the oil becomes" heated also sothat the oil becomes less viscous;

Inasmuch as the ballis in contact at all larities in-construction givesa true push action between the tappet and the valve stein so that thereis no side slapaction in the valve stem or push rod. The constructionmay be Iadj usted for clearance in a mannerquite-sirnioperationand isnot used to'e ect a cushion but is used solely to keep the ballincontact nected directly with the valve stem. The spring may even bedispensed with and theball may be conto theivalve stem but so that itcan twist with respect thereto.

A modified form of the invention is' shown in Fig. 4 whefin the ball 10.and the cooperating socket 11 are appreciably less than half ahemisphere in construction. This form is found to also be. satisfactory,and while the restriction to the flow of oil in and out of the socket isnot present in the degree which it is present in the construction shownin Fig. 2, the balland socket do make a sur-. face to surface contactand-the film of oil between the .two acts'as a cushion- .In'both formsof the invention the film of oil practically, eliminates any actual.metal to metal contact.

The construction as'shown hereinis one. found in internal combustion en;gins of the L-head or T-head type, but this commonly construction mayalso be used on engines which employ valves otherwise located'withoutrequiring any change in the structure.

It is within the invention to reverse the position of the bail memberand its socket as regards the valve stem and push red, as this s merelya reversal of parts;

I claim: a

1. In a valve construction, the combination of a valve having a stemmember, a push rod member, a socket in one of these members, a flatsided,ball in the socket, means for.

maintaining the fiat side of the ball in contact with the o'pp'ositemember, means for retaining a quantity ef oil adjacent the ball andsocket, said first mentioned means being adapted to lift the ballpartially from its socket when the push rod retracts from the stem,whereby the oilflows between the socket and ball member to provide anoil cushion between the ball and socket member.

acing means providing a In avalve construction, thecoinbination of avalvehaving a stem member, a push rod member'for' actuating the valve,one of these members being provided with a socket, 'a flat sided ball inthe socket, spring means in the socket tending normal-ly-tolift the ball"from the; socket and holdthe same in contact with the other ofthe saidmembers, meansfor retaininga quantityof oil adjacent the ball and"socket member, the said members being 7 coordinated so that when thepush rod isretract-ed from the stemmember there is a clear-' ancebetween the ball and socket to permit the I oil to flowin between theball and socket to thus'provide an oil cushion between the two. '3, In avalve construction','tlfe combination ofa valvehaving a valve stem, apush rod,

socket in the end of the push. rod, a fiat sided ball in the socket haveing continuous contact with the end of the valve stem and having aclearance with regardtoits socket when'thepush'rod is. re-

tracted from the valve stem,\and-means for retaining a quantity of-oiladjacent-the ball and .socket, some I of which fldws into the socketwhen. the ball is cleared therefrom,

whereby to providean'oil cushion between the two.

4. In afvalve construction, theco mbination of a valve having a stem,"apush rod sl'idably arranged to actuate the valve by contacting with thestem, means providing a closed socket in the end of the push rod whichwill retain-a fluid, a ballmember in the socket, means for normallylifting the ball from its socket and holding the same in contact withthevalve stem, there being a clearance in thearrangement ofparts so thatv the ball is lifted from .the socket when the push rod is retractedfrom the stem, means or retaining a quantity of fluid adjacent thesocket; some of which flows into the socket when theballis so liftedtherefrom, whereb to rovide a liquid cushion-between the ba 1 antsocket.

5. In a valve construction, the combina tion of a valve having a stem, apush rod sli'dably arranged to actuate the valve by contacting with thestem, --means"provi ing a closed socket in the end of the push rod whichwill retain a fluid, a ball member in the socket, 'means for normallylifting the ball from its socket and holding the samein contact with thevalve stem, there being a clearance in the arrangement of parts so thatthe ball-is lifted from the socket when the push rod is retracted fromthe'stem, means for'retaining a quantity of oil adjacent the socket,some of which flows into the socket when the ball is so liftedtherefrom, whereby to provide a cushion between the ball and socket,said ball and "socket being substantially hemis hericalinshape to thusprovide'near the e es of the socket a restricted passageway bgtweenthe-ball and socket to thus effect and socket together. 6. In a valveconstruction, the combinat on of a valve having a stem, a push rodrorelatively. slow egress of oil from the socket es to bring the ballwhen the, push rod mov vided with a'socket in its end; a fiat sided allin the socket, said socket being providedwith e from the valve stem,whereby such clearance permits the spring tolift the ball from its- .15socket, means for retaining a quantity of oil a well, a spring in this.well contacting with the ball and for maintaining the flat side vthereof in contact with the end of thefvalve' stem,.theparts beingarranged to'provide a clearance when the pushrod' is retracted 1adjacent the socket, some of which flows into the socket when theball islifted therefrom whereby an oilcushion is efiected between the ball andsocket when the push rod moves to 20 bring the two together and'actuatethe valve.

In 'test-imon whereof I afiixmy signature. XDRIAN ABBOTT, Jr.

